1. Field of the Invention
The present invention relates to a passenger detection system. More particularly, the present invention relates to a passenger detection system used to determine whether or not to activate an airbag apparatus provided in a car or other vehicle.
2. Background Information
A car or other vehicle is provided with a seat for a passenger to sit on, and an airbag apparatus configured and arranged to protect a seated passenger is provided with respect to the seat. Such an airbag apparatus is controlled by an airbag controller.
Regarding an airbag system like that just mentioned, the idea of providing a passenger detection system to determine if the airbag apparatus should be activated based on the passenger has already been considered in, for example, Japanese Patent Number 4339368.
This passenger detection system has a load sensor installed peripherally to the seat and a passenger detection controller configured to determine whether or not the airbag apparatus should be activated by determining if a passenger is sitting in the seat based on a load detection signal from the load sensor. The determination result obtained by the passenger detection controller is conveyed to the aforementioned airbag controller and used in a control executed by the airbag controller.
With such a passenger detection system, the passenger detection controller determines that a passenger is seated and the airbag apparatus should be activated when the load detection signal from the load sensor is larger than a preset internal threshold value and determines that a passenger is not seated and the airbag apparatus should not be activated when the load detection signal is smaller than the threshold value.
In this way, the airbag controller executes a control such that the airbag apparatus is activated when a passenger is sitting in the seat and not activated when a passenger is not sitting on the seat.